Fan blade assemlby

ABSTRACT

A fan blade assembly comprises: a motor-mounting seat and a plurality of spaced-apart fan blades extending from a periphery of the motor-mounting seat. The fan blades each are provided with a vibration-blocking unit in the form of a concave structure, which makes the fan blades become a non-flat structure. The vibration-blocking unit reduces the vibration and noise of the fan blade assembly, it further increases the structural strength while relatively reducing the thickness of the fan blades, so that the material cost of the fan blades is reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fan, and more particularly to a fan blade assembly.

2. Description of the Prior Art

Fan is an indispensible commodity to people's daily life. Wind noise is also an important consideration (besides the air moving capacity) when choosing a fan. A conventional fan blade structure 10, as shown in FIG. 1, is formed by fan blades 12 extending from the periphery of a connecting portion 11 of the motor. These fan blades 12 are flat and smooth and have a certain length, so noise and vibration are inevitable when the fan blades 12 are used. Increasing the thickness of the fan blades 12 helps noise and vibration reduction; however, it also increases the material cost and the weight of the fan blades. Furthermore, the increased weight of the fan blades increases, it requires the motor to output more power, causing increase in use cost.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a fan blade assembly capable of reducing vibration and noise, and also reducing manufacturing cost.

To achieve the above object, a fan blade assembly in accordance with the present invention comprises: a motor-mounting seat and a plurality of spaced-apart fan blades extending from a periphery of the motor-mounting seat. The fan blades each include a connecting edge, an opposite outer edge, and a leading edge and a trailing edge between the connecting edge and the opposite outer edge. The connecting edge is connected to the periphery of the motor-mounting seat, a vibration-blocking unit is formed in each of the fan blades and extends from the trailing edge to the leading edge, making the fan blades become a non-flat structure. The vibration-blocking unit has a length smaller than half of a length of the trailing edge.

The vibration-blocking unit is a concave structure and can reduce the vibration and noise of the fan blade assembly, it further increases the structural strength while relatively reducing the thickness of the fan blades, so that the material cost of the fan blades is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional fan blade assembly;

FIG. 2 is a perspective view of a fan blade assembly in accordance with the present invention;

FIG. 3 is a cross sectional view of the fan blade assembly in accordance with the present invention;

FIG. 4 is an enlarged view of a part of FIG. 3; and

FIG. 5 shows that the fan blade assembly in accordance with the present invention is disposed on a fan support.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

Referring to FIGS. 2-4, a fan blade assembly 20 in accordance with the present invention comprises a motor-mounting seat 21 and a plurality of spaced-apart fan blades 22 extending from a periphery of the motor-mounting seat 21. The motor-mounting seat 21 is formed with a through hole 211 for insertion of a shaft of a fan motor. The fan blades 22 each include a connecting edge 221, an opposite outer edge 222, and a leading edge 224 and a trailing edge 223 between the connecting edge 221 and the opposite outer edge 222. The connecting edge 221 is connected to the periphery of the motor-mounting seat 21, and the opposite outer edge 222 is arc-shaped. A vibration-blocking unit 225 in the form of an arc-shaped concave is formed in each of the fan blades 22 and extends from the trailing edge 223 to the leading edge 224, which makes the fan blades 22 become a non-flat structure. The vibration-blocking unit 225 has a length D1 smaller than half of a length D2 of the trailing edge 223.

The fan blade assembly 20 is mounted on a fan support X1 in such a manner that the motor-mounting seat 21 is connected to the fan motor X2, as shown in FIG. 5, and when the fan motor X2 rotates, it will drive the motor-mounting seat 21 and the fan blades 22 to rotate. When rotating, the trailing edges 223 of the fan blades 22 will cause wind shear. Since the opposite outer edge 222 is located furthest from the connecting edge 221, wind shear caused vibration will start first from the opposite outer edge 222 and then will be transmitted toward the connecting edge 221. When transmitted to the vibration-blocking unit 225, the vibration will be stopped by vibration-blocking unit 225 from further transmitting to the connecting edge 221 since the vibration-blocking unit 225 is a concave structure making the fan blades 22 become a non-flat structure, substantially reducing the vibration of the fan blade assembly 20 as well as the noise caused. Furthermore, the concave vibration-blocking unit 225 increases the structural strength while relatively reducing the thickness of the fan blades 22, so that the material cost of the fan blades 22 is reduced. More importantly, when the concave vibration-blocking unit 225 reduces the vibration, noise, and the thickness of the fan blades 22, the power of the fan motor required to drive the fan blade assembly 20 is also reduced, and a small power fan motor has a relative low cost.

For example, a conventional 14-inch fan blade assembly approximately weighs 168 grams and produces noise of 38-40 dB at the fan motor speed of 1050 RPM (revolutions per minute). However, a 14-inch fan blade assembly in accordance with the present invention can be made as light as 132 grams and produces noise of only 19-20 dB at the same speed of 1050 RPM.

While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A fan blade assembly comprising: a motor-mounting seat and a plurality of spaced-apart fan blades extending from a periphery of the motor-mounting seat, the fan blades each including a connecting edge, an opposite outer edge, and a leading edge and a trailing edge between the connecting edge and the opposite outer edge, the connecting edge being connected to the periphery of the motor-mounting seat, a vibration-blocking unit being formed in each of the fan blades and extending from the trailing edge to the leading edge, making the fan blades become a non-flat structure, the vibration-blocking unit having a length smaller than half of a length of the trailing edge.
 2. The fan blade assembly as claimed in claim 1, wherein the motor-mounting seat is formed with a through hole for insertion of a shaft of a fan motor.
 3. The fan blade assembly as claimed in claim 1, wherein the opposite outer edge is arc-shaped.
 4. The fan blade assembly as claimed in claim 1, wherein the vibration-blocking unit is an arc-shaped concave.
 5. The fan blade assembly as claimed in claim 1, wherein a periphery of the vibration-blocking unit is arc-shaped.
 6. The fan blade assembly as claimed in claim 1, wherein the fan blade assembly is mounted on a fan support, and the motor-mounting seat is connected to the fan motor. 